A METHANOL DIOXYGEN BIOFUEL CELL THAT USES NAD(+)-DEPENDENT DEHYDROGENASES AS CATALYSTS - APPLICATION OF AN ELECTRO-ENZYMATIC METHOD TO REGENERATE NICOTINAMIDE ADENINE-DINUCLEOTIDE AT LOW OVERPOTENTIALS/

Diaphorase catalyzes efficiently the oxidation of NADH to NAD(+) by be nzylviologen. This reaction was used to regenerate the NAD(+) required for the biocatalyzed oxidation of methanol to CO2 using NAD(+)-depend ent dehydrogenases. A methanol/dioxygen biofuel cell was assembled usi ng these bioreactions in the anode compartment. The open-circuit volta ge of the cell was 0.8 V, and the maximum power output of the cell was 0.67 mW/cm(2) of graphite at 0.49 V. These results reflect the low ov erpotential at which NADH is oxidized and demonstrate a new approach t o lowering voltage losses in biofuel cells due to activation overpoten tials. (C) 1998 Elsevier Science S.A.